Sequence A261220 shown in factorial base: a(n) = A007623(A261220(n)).

Terms

a(0) =0a(1) =1a(2) =10a(3) =20a(4) =100a(5) =101a(6) =200a(7) =220a(8) =300a(9) =310a(10) =1000a(11) =1001a(12) =1010a(13) =1020a(14) =2000a(15) =2001a(16) =2200a(17) =2300a(18) =3000a(19) =3020a(20) =3100a(21) =3300a(22) =4000a(23) =4010a(24) =4100a(25) =4200a(26) =10000a(27) =10001a(28) =10010a(29) =10020